1. Field
Exemplary embodiments relate to semiconductor devices and methods of manufacturing the semiconductor devices. More particularly, exemplary embodiments relate to semiconductor devices having a dummy gate structure and methods of manufacturing the dummy gate structure and the semiconductor devices.
2. Description of the Related Art
Oftentimes, high voltages are applied to substrates of semiconductor devices. In order to enhance the ability of the devices to withstand the high voltages without damage, gate structures formed on a region of a substrate to which a high voltage is applied may be formed to have a low density. As a result of the low density of the gate structures, an insulation layer covering the gate structures may have a height difference according to position on the device. In order to reduce the height difference, dummy gate structures may be formed between the actual gate structures that cause the height difference.
However, the dummy gate structure is usually formed on an isolation layer on the substrate. In order to lower the effective field oxide height (EFH) to reduce cell interference, the isolation layer may be formed to have a height lower than the top surface of the substrate. As a result, the dummy gate structure may have a height different from that of the gate structures, so that the height difference of the insulation layer covering the gate structures and the dummy gate structure may not be effectively reduced.